A method and a control apparatus for driving a lamp 14 in a lighting system, in particular a lamp having a fast response to a change of an amount of energy supplied through the lamp, in which a device controller 8 is connected with the lamp 14. The device controller 8 receives data values from a system controller 2 to change a light output level of the lamp 14. Upon receiving a data value which is different from a previously received data value the device controller calculates additional data values and distribute the additional data values in a following time interval to smoothen a transition between different light output levels of the lamp 14.